Influence of Healing Time on the Outcomes of Alveolar Ridge Preservation Using a Collagenated Bovine Bone Xenograft: A Randomized Clinical Trial

AIM To evaluate the healing outcomes in non-molar post-extraction sockets filled with deproteinized bovine bone mineral with collagen (DBBM-C) as a function of time. MATERIALS AND METHODS Patients in need of non-molar tooth extraction were randomly allocated into one of three groups according to the total healing time (A - 3 months; B - 6 months; C - 9 months). The effect of alveolar ridge preservation (ARP) therapy via socket filling using DBBM-C and socket sealing with a porcine collagen matrix (CM) was assessed based on a panel of clinical, digital, histomorphometric, implant-related, and patient-reported outcomes. RESULTS A total of 42 patients completed the study (n=14 in each group). Histomorphometric analysis of bone core biopsies obtained at the time of implant placement showed a continuous increase in the proportion of mineralized tissue with respect to non-mineralized tissue, and a decrease in the proportion of remaining xenograft material over time. All volumetric bone and soft tissue contour assessments revealed a dimensional reduction of the alveolar ridge overtime affecting mainly the facial aspect. Linear regression analyses revealed that baseline buccal bone thickness is a strong predictor of bone and soft tissue modeling. Ancillary bone augmentation at the time of implant placement was needed in 16.7% of the sites (A:2; B:1; C:4). Patient-reported discomfort and wound healing index scores progressively decreased over time and was similar across groups. CONCLUSIONS Healing time influences the proportion of tissue compartments in non-molar post-extraction sites filled with DBBM-C and sealed with a CM. A variable degree of alveolar ridge atrophy, affecting mainly the facial aspect, occurs even after performing ARP therapy. These changes are more pronounced in sites exhibiting thin facial bone (≤1mm) at baseline (Clinicaltrials.gov NCT03659617). This article is protected by copyright. All rights reserved.